{
uchar b,c
c=16
while(1>
{
hang1=0 hang2=1 hang3=1 hang4=1 P0|=0xf0 b=P0 b&=0xf0 if(b!=0xf0>
{
delay(10> P0|=0xf0 b=P0 b&=0xf0 if(b!=0xf0>
{
switch(b>
{
case 0xe0:c=0
case 0xd0:c=1
case 0xb0:c=2
case 0x70:c=3
default:c=16
}
}
}
P3&=0xf0
P2=a[c] hang1=1 hang2=0 hang3=1 hang4=1 P0|=0xf0 b=P0 b&=0xf0 if(b!=0xf0>
{
delay(10> P0|=0xf0 b=P0
break
break
break
break